In the Nick of Time-Emergency Front-of-Neck Airway Access

Emergency front-of-neck access refers to all techniques that deliver oxygen into the airway lumen through the anterior neck structures and encompasses access both through the cricothyroid membrane and the tracheal wall. There has yet to be a universal agreement regarding the preferred technique. A surgical incision is currently the most common approach in prehospital and in-hospital care. This review intends to review and summarize the existing clinical, basic science, and societal guidelines for eFONA.

Effect of supraglottic jet oxygenation and ventilation on hypoxemia in patients undergoing endoscopic surgery with sedation: A meta-analysis of randomized controlled trials

BACKGROUND

Nasal cannulas and face masks are common oxygenation tools used in conventional oxygen therapy for patients undergoing endoscopic surgery with sedation. However, as a novel supraglottic ventilation technique, the application of supraglottic jet oxygenation and ventilation (SJOV) in endoscopic surgery has not been well established.

METHOD

We searched six electronic databases from inception to January 16, 2024, to assess the oxygenation/ventilation efficacy and side effects of the of SJOV in endoscopic surgery. The primary outcome was the incidence of hypoxemia. The secondary outcomes were the incidence of respiratory depression and adverse effects (nasal bleeding, sore throat, and dry mouth).

RESULTS

Nine trials involving 2017 patients were included. The results demonstrated that the incidence of hypoxemia was lower in the SJOV group compared with the conventional oxygen therapy (COT) group [9 trails; 2017 patients; risk ratio (RR) = 0.18; 95% confidence interval (CI), (0.11-0.28)]. Subgroup analyses showed that SJOV reduced the incidence of hypoxemia in the high-risk group but had no effect on the low-risk group. The incidence of respiratory depression is lower in SJOV than in COT, but has increased side effects such as dry mouth. There was no statistically significant difference in nose bleeding or sore throat between the two groups.

CONCLUSION

Compared with the COT, the SJOV decreased the incidence of hypoxemia in high-risk patients during endoscopic surgery with sedation. There was an increased risk of dry mouth, but not of nose bleeding or sore throat, during endoscopic surgery under sedation.

A case series of the Royal Perth Hospital cannula-first approach in the 'can't intubate, can't oxygenate' scenario

At the Royal Perth Hospital, we have been developing and teaching a can't intubate, can't oxygenate (CICO) rescue algorithm for over 19 years, based on live animal simulation. The algorithm involves a 'cannula-first' approach, with jet oxygenation and progression to scalpel techniques if required in a stepwise fashion. There is little reported experience of this approach to the CICO scenario in humans. We present eight cases in which a cannula-first Royal Perth Hospital approach was successfully implemented during an airway crisis. We recommend that institutions teach and practice this approach; we believe it is effective, safe and minimally invasive when undertaken by clinicians who have been trained in it and have immediate access to the requisite equipment. The equipment is low cost, comprising a 14G Insyte cannula, saline, 5 ml syringe and a Rapid-O2. Training can be provided using low-fidelity manikins or part-task trainers.

Simulation in airway management teaching and training

There is a gradual shift in training and teaching methods in the medical field. We are slowly moving from the traditional model and adopting active learning methods like simulation-based training. Airway management is an essential clinical skill for any anaesthesiologist, and a trained anaesthesiologist must perform quick and definitive airway management using various techniques. Airway simulations have been used for the past few decades. It ensures active involvement, upgrading the trainees' airway management knowledge and skills, including basic airway skills, invasive procedures, and difficult clinical scenarios. Trainees also learn non-technical skills such as communication, teamwork, and coordination. A wide range of airway simulators are available. However, texture surface characteristics vary from one type to another. The simulation-based airway management training requires availability, understanding, faculty development, and a structured curriculum for effective delivery. This article explored the available evidence on simulation-based airway management teaching and training.

Difficult Tracheal Intubation and Airway Outcomes after Radiation for Nasopharyngeal Carcinoma

OBJECTIVE

The aim of the study was to characterize the incidence and management of difficult tracheal intubations (DTIs) in nasopharyngeal carcinoma (NPC) after primary radiation therapy (RT).

METHODS

The study was a retrospective review of airway assessment and outcomes in post-RT NPC patients. Primary analysis was performed on patients who underwent post-RT procedures, who were split into non-DTI and DTI groups. Patients were classified as DTI if they (i) required >1 attempt to intubate, (ii) failed to be intubated, or (iii) experienced complications attributed to airway management. Secondary analysis was performed between patients who underwent post-RT procedures (procedure group) and those who did not (control group).

RESULTS

One-hundred and fifty patients were included, and 71.3% underwent post-RT procedures, with no differences in characteristics between the procedure and control groups. One-hundred and fifty procedures were identified, and 28.0% were categorized as DTI. There was no difference in patient characteristics or airway assessment measures between DTI and non-DTI groups. Regression analysis revealed concurrent cervical mobility restriction, and trismus increased DTI incidence by 7.1-fold (p = 0.011). Being non-White was an independent predictor of DTI. The incidence of high-grade intraoperative laryngoscopic view was lower in the non-DTI compared to the DTI group (20.4% vs. 64.3%, p < 0.0001). Failure to intubate occurred in 2.0% of cases, and 6.0% cases had perioperative complications. Based on preoperative assessment, sensitivity of predicting DTI was 54.8% and specificity was 63.9%.

CONCLUSION

NPC patients frequently undergo post-RT procedures requiring complex airway management. Rates of DTI and failed intubation are significantly higher than those in the general surgical population, and the ability to predict DTI with standard preoperative airway measures is poor.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:120-126, 2024.

Concomitant Intubation with Minimal Cuffed Tube and Rigid Bronchoscopy for Severe Tracheo-Carinal Obstruction

BACKGROUND

Our aim was to report on the use of an innovative technique for airway management utilizing a small diameter, short-cuffed, long orotracheal tube for assisting operative rigid bronchoscopy in critical airway obstruction.

METHODS

We retrospectively reviewed the clinical data of 36 patients with life-threatening critical airway stenosis submitted for rigid bronchoscopy between January 2008 and July 2021. The supporting ventilatory tube, part of the Translaryngeal Tracheostomy KIT (Fantoni method), was utilized in tandem with the rigid bronchoscope during endoscopic airway reopening.

RESULTS

Indications for collateral intubation were either tumors of the trachea with near-total airway obstruction (13), or tumors of the main carina with total obstruction of one main bronchus and possible contralateral involvement (23). Preliminary dilation was necessary before tube placement in only 2/13 patients with tracheal-obstructing tumors (15.4%). No postoperative complications were reported. There was one case of an intraoperative cuff tear, with no further technical problems.

CONCLUSIONS

In our experience, this innovative method proved to be safe, allowing for continuous airway control. It enabled anesthesia inhalation, use of neuromuscular blockage and reliable end-tidal CO2 monitoring, along with protection of the distal airway from blood flooding. The shorter time of the procedure was due to the lack of need for pauses to ventilate the patient.

Updated guideline on equipment to manage difficult airways: Australian and New Zealand College of Anaesthetists

The Australian and New Zealand College of Anaesthetists (ANZCA) recently reviewed and updated the guideline on equipment to manage a difficult airway. An ANZCA-established document development group, which included representatives from the Australasian College for Emergency Medicine and the College of Intensive Care Medicine of Australia and New Zealand, performed the review, which is based on expert consensus, an extensive literature review, and bi-nationwide consultation. The guideline (PG56(A) 2021, https://www.anzca.edu.au/getattachment/02fe1a4c-14f0-4ad1-8337-c281d26bfa17/PS56-Guideline-on-equipment-to-manage-difficult-airways) is accompanied by a detailed background paper (PG56(A)BP 2021, https://www.anzca.edu.au/getattachment/9ef4cd97-2f02-47fe-a63a-9f74fa7c68ac/PG56(A)BP-Guideline-on-equipment-to-manage-difficult-airways-Background-Paper), from which the current recommendations are reproduced on behalf of, and with the permission of, ANZCA. The updated 2021 guideline replaces the 2012 version and aims to provide an updated, objective, informed, transparent, and evidence-based review of equipment to manage difficult airways.

Parameters of high-frequency jet ventilation using a mechanical lung model

High frequency jet ventilationis a mechanical lung ventilation method which uses a relatively high flow usually through an open system. This work examined the effect of high-frequency jet ventilation on respiratory parameters of an intubated patient simulated using a high-frequency jet ventilator attached to a ventilation monitor for measurements of ventilation parameters. The series of experiments altered specific parameters each time (respiratory rate, inspiratory-expiratory (I:E) ratio, and inspiratory pressure), under different lung compliances. A reduction of minute ventilation was observed alongside a rise in respiratory rate, with low airway pressures over the entire range of lung compliances. In addition, an I:E ratio of 2:1 to 1:1; and the tidal and minute volumes were directly related to the inspiratory pressure over all compliance settings. To conclude, the respiratory mechanics in high-frequency jet ventilation are very different from those of conventional rate ventilation in a lung model. Further studies on patients and/or a biological model are needed to investigate pCO2 and end-tidal carbon-dioxide during high-frequency jet ventilation.

Cannula cricothyroidotomy in the impalpable neck: An observational study of simulated 'can't intubate, can't oxygenate' scenarios by teams following a cannula-first algorithm in live anaesthetised pigs

Live animal models can be used to train anaesthetists to perform emergency front-of-neck-access. Cannula cricothyroidotomy success reported in previous wet lab studies contradicts human clinical data. This prospective, observational study reports success of a cannula-first 'can't intubate, can't oxygenate' algorithm for impalpable anatomy during high fidelity team simulations using live, anaesthetised pigs.Forty-two trained anaesthesia teams were instructed to follow the Royal Perth Hospital can't intubate, can't oxygenate algorithm to re-oxygenate a desaturating pig with impalpable neck anatomy (mean (standard deviation, SD) 16.2 (3.5) kg); mean (SD) tracheal internal diameter 11 (1.4) mm. Teams were informed that failure would prompt veterinary-led euthanasia.All teams performed percutaneous cannula cricothyroidotomy as the initial technique, with a median (interquartile range, IQR (range)) start time of 42 (35-50 (24-93)) s. First-pass percutaneous cannula success was 29% to both insufflate tracheal oxygen and re-oxygenate. Insufflation success improved with repeated percutaneous attempts (up to three), but prolonged hypoxia time increasingly necessitated euthanasia (insufflation 57%; re-oxygenation 48%). First, second and third percutaneous attempts achieved insufflation at median (IQR (range)) 74 (64-91 (46-110)) s, 111 (95-136 (79-150)) s and 141 (127-159 (122-179)) s, respectively. Eighteen teams failed with percutaneous cannulae and performed scalpel techniques, predominantly dissection cannulation (n = 17) which achieved insufflation in all cases (insufflation 100%; re-oxygenation 47%). Scalpel attempts were started at median (IQR (range)) 142 (133-218 (97-293)) s and achieved insufflation at 232 (205-303 (152-344)) s.While percutaneous cannula cricothyroidotomy could rapidly re-oxygenate, the success rate was low and teams repeated attempts beyond the recommended 60 s time frame, delaying transition to the more successful dissection cannula technique. We recommend this 'cannula-first' can't intubate, can't oxygenate algorithm adopts a 'single best effort' strategy for percutaneous cannula, with failure prompting a scalpel technique.

Success and Time to Oxygen Delivery for Scalpel-Finger-Cannula and Scalpel-Finger-Bougie Front-of-Neck Access: A Randomized Crossover Study With a Simulated "Can't Intubate, Can't Oxygenate" Scenario in a Manikin Model With Impalpable Neck Anatomy

BACKGROUND

Emergency front-of-neck access (FONA) is particularly challenging with impalpable neck anatomy. We compared 2 techniques that are based on a vertical midline neck incision, followed by finger dissection and then either a cannula or scalpel puncture to the cricothyroid membrane.

METHODS

A manikin simulation scenario of impalpable neck anatomy and bleeding was created. Sixty-five anesthesiologists undergoing cricothyrotomy training performed scalpel-finger-cannula (SFC) and scalpel-finger-bougie (SFB) cricothyrotomy in random order. Primary outcomes were time to oxygen delivery and first-attempt success; data were analyzed using multilevel mixed-effects models.

RESULTS

SFC was associated with a shorter time to oxygen delivery on univariate (median time difference, -61.5 s; 95% confidence interval [CI], -84.7 to -38.3; P < .001) and multivariable (mean time difference, -62.1 s; 95% CI, -83.2 to -41.0; P < .001) analyses. Higher first-attempt success was reported with SFC than SFB (47 of 65 [72.3%] vs 18 of 65 [27.7%]). Participants also had higher odds at achieving first-attempt success with SFC than SFB (odds ratio [OR], 10.7; 95% CI, 3.3-35.0; P < .001). Successful delivery of oxygen after the "can't intubate, can't oxygenate" (CICO) declaration within 3 attempts and 180 seconds was higher (84.6% vs 63.1%) and more likely with SFC (OR, 5.59; 95% CI, 1.7-18.9; P = .006). Analyzing successful cases only, SFC achieved a shorter time to oxygen delivery (mean time difference, -24.9 s; 95% CI, -37.8 to -12.0; P < .001), but a longer time to cuffed tube insertion (mean time difference, +56.0 s; 95% CI, 39.0-73.0; P < .001). After simulation training, most participants preferred SFC in patients with impalpable neck anatomy (75.3% vs 24.6%).

CONCLUSIONS

In a manikin simulation of impalpable neck anatomy and bleeding, the SFC approach demonstrated superior performance in oxygen delivery and was also the preferred technique of the majority of study participants. Our study findings support the use of a cannula-based FONA technique for achieving oxygenation in a CICO situation, with the prerequisite that appropriate training and equipment are available.

Emergency Subglottic Airway Training and Assessment of Skills Retention of Attending Anesthesiologists With Simulation Mastery-Based Learning

BACKGROUND

Although included within the American Society of Anesthesiologists difficult airway algorithm, the use of "invasive airway access" is rarely needed clinically. In conjunction with highly associated morbidity and liability risks, it is a challenge for the average anesthesiologist to develop and maintain competency. The advancement of high-fidelity simulators allows for practice of rarely encountered clinical scenarios, specifically those requiring invasive subglottic airway techniques.

METHODS

Sixty board-certified academic anesthesiologists were enrolled and trained in dyads in a simulation-based, mastery-based learning (MBL) course directed at 2 emergency airway subglottic techniques: transtracheal jet ventilation (TTJV) and bougie cricothyrotomy (BC). Performance metrics included: pretest, posttest, specific skill step error tracking, and 15-month period retest. All were pretested and trained once on the Melker cricothyrotomy (MC) kit. All pretest assessment, training, posttesting, and 15-month retesting were performed by a single expert clinical and educational airway management faculty member.

RESULTS

Initial testing showed a success rate of 14.8% for TTJV, 19.7% for BC, and 25% for MC. After mastery-based practice, all anesthesiologists achieved successful invasive airway placement with TTJV, BC, and MC. Repeated performance of each skill improved speed with zero safety breaches. BC was noted to be the fastest performed technique. Fifteen months later, retesting showed that 80.4% and 82.6% performed successful airway securement for TTJV and BC, respectively. For safety, average placement time and costs, MC was discarded after initial training results.

CONCLUSIONS

We discovered that only ~20% of practicing anesthesiologists were able to successfully place an invasive airway in a simulated life or death clinical setting. Using mobile simulation (training performed in department conference room) during a 2.5-hour session using mastery-based training pedagogy, we increased our success rate of invasive airway placement to 100%, while also increasing the successful speed to ventilation (TTJV, 32 seconds average; BC, 29 seconds average). Finally, we determined that there was a 15-month 80% retention rate of the airway skills learned, indicating that skills last at least a year before retraining is required using this training methodology.

Evaluation of a novel emergency front of neck access device in a benchtop model of obesity

BACKGROUND

Emergency front of neck access (eFONA) is a critical step in oxygenation in cases of unrelieved airway obstruction. Multiple techniques are used in clinical practice without agreement regarding the optimal approach. We evaluated a novel device, the Cric-Guide (CG), a channelled bougie introducer that enters the airway in a single action and compared it with a scalpel-bougie-tube (SBT) technique in laboratory benchtop model.

METHODS

Seven anaesthesiologists attempted eFONA on both obese and non-obese models using both techniques in randomized order on an excised porcine trachea with an intact larynx with variable subcutaneous tissue depth. The primary outcome was successful tracheal cannulation. Secondary outcomes included false passage rate, time and tissue injury.

RESULTS

Anaesthesiologists performed 4 cricothyroidotomies on each model with each device. The CG was more successful in airway cannulation (47/56 [89.4%] vs. 33/56 [58.9%], P = 0.007). This difference was observed in the obese model only. The CG was associated with fewer false passages than the standard technique in the obese model (8/56 [14.3%] vs. 23/56 [41.1%], P = 0.006). There were no significant differences in time to completion or injury patterns between the techniques in the obese model, but the SBT was faster in the non-obese model. There was no difference in the proportion of specimens injured.

CONCLUSION

The Cric-Guide device was more successful than the standard SBT technique in airway cannulation in an obese neck model and with equivalent frequency and distribution of injury but performed equivalently in the non-obese model.

Ventilation through small-bore airways in children by implementing active expiration

Management of narrowed airways can be challenging, especially in the smallest patients. This educational review focusses on active expiration through small-bore airways with the Ventrain (Ventinova Medical, Eindhoven, The Netherlands). Manual ventilation with the Ventrain establishes inspiratory and expiratory flow control: By setting an appropriate flow, the volume of gas insufflated over time can be controlled and expiration through a small-bore airway is expedited by jet-flow generated suction, coined "expiratory ventilation assistance" (EVA). This overcomes the inherent risks of emergency jet ventilation especially in pediatric airway emergencies. Active expiration by EVA has been clinically introduced to turn a "straw in the airway" into a lifesaver allowing not only for quick and reliable reoxygenation but also adequate ventilation. As well as managing airway emergencies, ventilating through small-bore airways by applying EVA implements new options for pediatric airway management in elective interventional procedures. Safe application of EVA demands a thorough understanding of the required equipment, the principle and function of the Ventrain, technical prerequisites, clinical safety measures, and, most importantly, appropriate training.

Prehospital Surgical Airway Management: An NAEMSP Position Statement and Resource Document

Bag-valve-mask ventilation and endotracheal intubation have been the mainstay of prehospital airway management for over four decades. Recently, supraglottic device use has risen due to various factors. The combination of bag-valve-mask ventilation, endotracheal intubation, and supraglottic devices allows for successful airway management in a majority of patients. However, there exists a small portion of patients who are unable to be intubated and cannot be adequately ventilated with either a facemask or a supraglottic airway. These patients require an emergent surgical airway. A surgical airway is an important component of all airway algorithms, and in some cases may be the only viable approach; therefore, it is imperative that EMS agencies that are credentialed to manage airways have the capability to perform surgical airways when appropriate. The National Association of Emergency Medical Services Physicians (NAEMSP) recommends the following for emergency medical services (EMS) agencies that provide advanced airway management.A surgical airway is reasonable in the prehospital setting when the airway cannot be secured by less invasive means.When indicated, a surgical airway should be performed without delay.A surgical airway is not a substitute for other airway management tools and techniques. It should not be the only rescue option available.Success of an open surgical approach using a scalpel is higher than that of percutaneous Seldinger techniques or needle-jet ventilation in the emergency setting.

Emergency Front-of-Neck Airway Rescue Via the Cricothyroid Membrane: A High-Resolution Computed Tomography Study of Airway Anatomy in Adults

BACKGROUND

Emergency front-of-neck airway rescue is recommended in a can't intubate, can't oxygenate clinical scenario. Cannula cricothyroidotomy has been reported as having a high failure rate. Our primary aim was to estimate the angle of the trachea in relation to the horizontal axis in a simulated emergency front-of-neck airway rescue position. Our secondary aims were to estimate the optimal cannula angle of approach and evaluate the anatomical relationship of the cricothyroid membrane (CTM) to adjacent structures. We also assessed whether the CTM lies above or below the neck midpoint, a point equidistant from the suprasternal notch (SSN), and the chin surface landmarks. All measurements were compared between the male and female subjects.

METHODS

Subjects having elective computed tomography of their thorax were consented to have extension of the computed tomography to include their neck. A preliminary radiation dose and risk assessment deemed the additional radiation to be of very low risk (level IIa). Subjects were positioned supinely on the computed tomography table. Standard neck extension was achieved by placing a pillow under the scapulae and a rolled towel under the neck to simulate emergency front-of-neck airway rescue positioning.

RESULTS

Fifty-two subjects were included in this study: 31 men and 21 women. The mean angle of the trachea in relation to the horizontal axis was 25.5° (95% confidence interval [CI], 21.8-29.1) in men and 14.0° (95% CI, 11.5-16.5) in women. The mean minimum angles required for hypothetical cannula cricothyroidotomy for men and women were 55.2° (95% CI, 51.8-58.7) and 50.5° (95% CI, 45.4-55.6), respectively. The CTM was located lower in the neck in men compared to women. The CTM was located below the neck midpoint in 30 of 30 (100%) male subjects and 11 of 20 (55%) female subjects (P < .001).

CONCLUSIONS

The trachea angulates posteriorly in a simulated emergency front-of-neck airway rescue position in supine subjects and to a greater degree in men compared to women (P < .001). The minimum angle required for hypothetical cannula cricothyroidotomy was >45° in the majority (75%) of subjects studied. A steeper cannula angle of approach may be more reliable and warrants further clinical study. If airway anatomy is indistinct and performing a vertical scalpel cricothyroidotomy, consideration should be given to performing this incision lower in the neck in men compared to women.

Jet flow rate and needle position govern distal airway pressures during low-frequency jet ventilation

OBJECTIVES

Although jet ventilation is frequently used during surgery for airway stenosis, little is known about distal airway pressures during jet ventilation. The objective of the study is to determine how jet pressure, flow rate, and position of the ventilation needle relate to distal airway pressure magnitude and homogeneity.

METHODS

Two 3D models of the first five generations of the human airway tree were created. One is a duplicate of a human airway from a 15-year-old healthy male's computed tomography scan, and the other is an idealized symmetric model of human lung morphometry. Pressure transducers measured fifth-generation distal airway pressures in both models. A computer-controlled jet needle positioning system was used to ventilate the lung casts. The effects of jet needle position, jet pressure, and jet flow rate on distal airway pressure and homogeneity were measured.

RESULTS

Total entrained jet flow rate was the most reliable predictor of distal airway pressure. Pressure supplied to the jet ventilation needle had a positive linear relationship with distal airway pressure; however, this relationship was dependent on the jet needle flow resistance. As the ventilation needle moved closer to the tracheal wall, ventilation homogeneity decreased. Depth into the trachea was positively correlated with sensitivity of the needle to the tracheal wall.

CONCLUSION

In this model, total entrained jet flow rate is a more robust predictor of distal airway pressure than jet inlet pressure. More homogeneous ventilation was observed in our model with the ventilation needle centered in the proximal region of the trachea.

Ventilation strategies for front of neck airway rescue: an in silico study

BACKGROUND

During induction of general anaesthesia a 'cannot intubate, cannot oxygenate' (CICO) situation can arise, leading to severe hypoxaemia. Evidence is scarce to guide ventilation strategies for small-bore emergency front of neck airways that ensure effective oxygenation without risking lung damage and cardiovascular depression.

METHODS

Fifty virtual subjects were configured using a high-fidelity computational model of the cardiovascular and pulmonary systems. Each subject breathed 100% oxygen for 3 min and then became apnoeic, with an obstructed upper airway. When arterial haemoglobin oxygen saturation reached 40%, front of neck airway access was simulated with various configurations. We examined the effect of several ventilation strategies on re-oxygenation, pulmonary pressures, cardiovascular function, and oxygen delivery.

RESULTS

Re-oxygenation was achieved in all ventilation strategies. Smaller airway configurations led to dynamic hyperinflation for a wide range of ventilation strategies. This effect was absent in airways with larger internal diameter (≥3 mm). Intrapulmonary pressures increased quickly to supra-physiological values with the smallest airways, resulting in pronounced cardio-circulatory depression (cardiac output <3 L min^-1 and mean arterial pressure <60 mm Hg), impeding oxygen delivery (<600 ml min^-1). Limiting tidal volume (≤200 ml) and ventilatory frequency (≤8 bpm) for smaller diameter cannulas reduced dynamic hyperinflation and gas trapping, preventing cardiovascular depression.

CONCLUSIONS

Dynamic hyperinflation can be demonstrated for a wide range of front of neck airway cannulae when the upper airway is obstructed. When using small-bore cannulae in a CICO situation, ventilation strategies should be chosen that prevent gas trapping to prevent severe adverse events including cardio-circulatory depression.

Supraglottic jet oxygenation and ventilation reduces desaturation during bronchoscopy under moderate to deep sedation with propofol and remifentanil: A randomised controlled clinical trial

BACKGROUND

Hypoxaemia is frequently seen during flexible bronchoscopies that are done with a nasal approach under the traditional sedation with propofol. This study investigated the potential benefits of supraglottic jet oxygenation and ventilation (SJOV) using the Wei nasal jet tube (WNJ) in reducing hypoxaemia in patients undergoing bronchoscopy under moderate to deep intravenous sedation using a propofol, lidocaine and remifentanil cocktail.

OBJECTIVES

Our primary objective was to evaluate the efficacy and complications of SJOV via the WNJ during flexible bronchoscopy under moderate to heavy sedation with propofol and remifentanil.

DESIGN

A randomised controlled clinical trial.

SETTING

The 180th Hospital of People's Liberation Army, Quanzhou, China, from 1 June to 1 November 2019.

PATIENTS

A total of 280 patients aged ≥18 years with American Society of Anesthesiologists' physical status 1 to 3 undergoing flexible bronchoscopy were studied.

INTERVENTIONS

Patients were assigned randomly into one of two groups, a nasal cannula oxygenation (NCO) group (n = 140) using a nasal cannula to deliver oxygen (4 l min-1) or the SJOV group (n = 140) using a WNJ connected to a manual jet ventilator to provide SJOV at a driving pressure of 103 kPa, respiratory rate 20 min-1, FiO2 1.0 and inspiratory:expiratory (I:E) ratio 1:2.

MAIN OUTCOME MEASURES

The primary outcome was an incidence of desaturation (defined as SpO2 < 90%) during the procedure. Other adverse events related to the sedation or SJOV were also recorded.

RESULTS

Compared with the NCO group, the incidence of desaturation in the SJOV group was lower (NCO 37.0% vs. SJOV 13.1%) (P < 0.001). Patients in the SJOV group had a higher incidence of a dry mouth at 1 min (13.1% vs. 1.5%, P < 0.001) than at 30 min (1.5% vs. 0%, P = 0.159) or at 24 h (0% vs. 0%). There was no significant difference between the groups in respect of sore throat, subcutaneous emphysema or nasal bleeding.

CONCLUSIONS

SJOV via a WNJ during flexible bronchoscopy under moderate to deep sedation with propofol and remifentanil significantly reduces the incidence of desaturation when compared with regular oxygen supplementation via a nasal cannula. Patients in the SJOV group had an increased incidence of transient dry mouth.

TRIAL REGISTRATION

Registered at www.chictr.org.cn (ChiCTR1900023514).

The Lost Airway

Management of the unanticipated difficult airway is one of the most relevant and challenging crisis management scenarios encountered in clinical anesthesia practice. Several guidelines and approaches have been developed to assist clinicians in navigating this high-acuity scenario. In the most serious cases, the clinician may encounter a failed airway that results from failure to ventilate an anesthetized patient via facemask or supraglottic airway or intubate the patient with an endotracheal tube. This dreaded cannot intubate, cannot oxygenate situation necessitates emergency invasive access. This article reviews the incidence, management, and complications of the failed airway and training issues related to its management.

Randomised comparison of Enk™ and Manujet™ for emergency tracheal oxygenation with a high-fidelity full-scale simulation

BACKGROUND

We aimed to compare time and difficulties of emergency tracheal oxygenation with Enk™ or Manujet™ by anaesthesiologists or intensivists, in a full-scale cannot ventilate and intubate scenarios on a SimMan3G™ high-fidelity patient simulator.

METHODS

After ethical committee approval and written informed consent, teams (two to three learners with at least one physician senior) participating at a difficult airway training with a massive sublingual haematoma scenario, were randomised in Enk™ (E) group (29 teams, 76 learners) and Manujet™ (M) group (31 teams, 84 learners) according to the device at disposal. Main criterion was time between taking device in hand and first insufflation delay. Data were medians [25-75%].

RESULTS

The handling-insufflation time was shorter with Enk™ than with Manujet™ (74 [54-87] seconds versus 95 [73-123] seconds (s), P=0.0112). The team number performing insufflation within one minute after device handling was higher in the E group (8, 27.6%) than in the M group (2, 6.4%) (P=0.0392) as well as the team number performing insufflation within 90s in the E group (22, 75.09%) than in the M group (12, 38.7%) (P=0.0047). In E group, 75% of learners reported no difficulty versus 58.8% in M group (P=0.0443). Insufflation frequency was high in both groups and higher than 12min^-1 in 51.7% of the teams.

CONCLUSION

In a simulation context, Enk™ use is faster and easier. A high insufflation rate was also in favour of Enk™ that generates lower airway pressures.

Airway Leads and Airway Response Teams: Improving Delivery of Safer Airway Management?

Purpose of Review

Airway management remains a source of significant morbidity and mortality. This review considers recent summaries of complications and looks toward strategies to improve practice using a coordinated approach.

Recent Findings

A safety gap can exist between national recommendations and local practice. A lack of attention to end tidal carbon dioxide has repeatedly contributed to airway mismanagement. Clinicians must be trained in newer airway devices (videolaryngoscopes or supraglottic airways) to use them effectively. Time must be found to teach rarely performed skills (e.g., front-of-neck access). Both larger and smaller hospitals have benefitted from an airway lead or response team, coordinating education programs, ensuring the adoption of guidelines, standardizing equipment, and recognizing the role of human factors and ergonomics.

Summary

Even in the twenty-first century, the incidence of airway-related morbidity and mortality can be reduced, by an institutionally supported, coordinated approach to the whole process of airway care.

The Ventrain Device: A Future Role in Difficult Airway Algorithms?

The Ventrain is a small, manually operated, single-use, inspiratory flow-adjustable ventilation device that generates positive pressure during inspiration and, through a Bernoulli effect within the device, active suction during expiration. It was designed to provide emergency ventilation during airway obstruction via narrow-bore cannulae. The device has been used successfully in elective procedures lasting >1 hour. It remains to be seen if its theoretical advantages in "can't intubate, can't oxygenate" (CICO) scenarios translate to reliable clinical benefit and allow inclusion in future airway algorithms. We advocate for regular simulation training and the detailed reporting of clinical experience with this encouraging new tool.

Management of Difficult Tracheal Intubation: A Closed Claims Analysis

BACKGROUND

Difficult or failed intubation is a major contributor to morbidity for patients and liability for anesthesiologists. Updated difficult airway management guidelines and incorporation of new airway devices into practice may have affected patient outcomes. The authors therefore compared recent malpractice claims related to difficult tracheal intubation to older claims using the Anesthesia Closed Claims Project database.

METHODS

Claims with difficult tracheal intubation as the primary damaging event occurring in the years 2000 to 2012 (n = 102) were compared to difficult tracheal intubation claims from 1993 to 1999 (n = 93). Difficult intubation claims from 2000 to 2012 were evaluated for preoperative predictors and appropriateness of airway management.

RESULTS

Patients in 2000 to 2012 difficult intubation claims were sicker (78% American Society of Anesthesiologists [ASA] Physical Status III to V; n = 78 of 102) and had more emergency procedures (37%; n = 37 of 102) compared to patients in 1993 to 1999 claims (47% ASA Physical Status III to V; n = 36 of 93; P < 0.001 and 22% emergency; n = 19 of 93; P = 0.025). More difficult tracheal intubation events occurred in nonperioperative locations in 2000 to 2012 than 1993 to 1999 (23%; n = 23 of 102 vs. 10%; n = 10 of 93; P = 0.035). Outcomes differed between time periods (P < 0.001), with a higher proportion of death in 2000 to 2012 claims (73%; n = 74 of 102 vs. 42%; n = 39 of 93 in 1993 to 1999 claims; P < 0.001 adjusted for multiple testing). In 2000 to 2012 claims, preoperative predictors of difficult tracheal intubation were present in 76% (78 of 102). In the 97 claims with sufficient information for assessment, inappropriate airway management occurred in 73% (71 of 97; κ = 0.44 to 0.66). A "can't intubate, can't oxygenate" emergency occurred in 80 claims with delayed surgical airway in more than one third (39%; n = 31 of 80).

CONCLUSIONS

Outcomes remained poor in recent malpractice claims related to difficult tracheal intubation. Inadequate airway planning and judgment errors were contributors to patient harm. Our results emphasize the need to improve both practitioner skills and systems response when difficult or failed tracheal intubation is encountered.

Emergency front of neck airway: What do trainers in the UK teach? A national survey

Background and Aims:

Front of neck airway (FONA) is the final step to deliver oxygen in the difficult airway management algorithms. The Difficult Airway Society 2015 guidelines have recommended a standardized scalpel cricothyroidotomy technique for an emergency FONA. There is a wide variability in the FONA techniques with disparate approaches and training. We conducted a national postal survey to evaluate current teaching, availability of equipment, experienced surgical help and prevalent attitudes in the face of a can’t intubate, can’t oxygenate situation.

Material and Methods:

The postal survey was addressed to airway leads across National Health Service hospitals in the United Kingdom (UK). In the anesthetic departments with no designated airway leads, the survey was addressed to the respective college tutors. A total of 259 survey questionnaires were posted.

Results:

We received 209 survey replies with an overall response rate of 81%. Although 75% of respondents preferred scalpel cricothyroidotomy, only 28% of the anesthetic departments considered in-house FONA training as mandatory for all grades of anesthetists. Scalpel-bougie-tube kits were available in 95% of the anesthetic departments, either solely or in combination with other FONA devices.

Conclusion:

The survey has demonstrated that a majority of the airway trainers in the UK would prefer scalpel cricothyroidotomy as emergency FONA. There is a significant variation and deficiency in the current levels of FONA training. Hence, it is important that emergency FONA training is standardized and imparted at a multidisciplinary level.

A Resuscitation Option for Upper Airway Occlusion Based on Bolus Transtracheal Lung Inflation

Background

Acute laryngospasm sufficient to cause obstructive apnea is a medical emergency that can be difficult to manage within the very short time available for establishing an airway. We have presented substantial evidence that laryngospasm-based obstructive apnea is the cause of sudden death in epilepsy, and airway management is particularly challenging during seizure activity.

Objective

We sought to determine if the transtracheal delivery of a bolus of oxygen or room air below the level of an obstruction to inflate the lungs could be an effective method to prolong the time available for responders seeking to establish a stable airway, and, if so, what could be learned about optimization of delivery parameters from a rat model.

Methods

Rats were fitted with a t-shaped tracheal tube for controlling access to air and for measuring airway pressures. After respiratory arrest from simulated laryngospasm, bolus transtracheal lung inflation with a volume of gas equivalent to half the vital capacity was delivered to the closed respiratory system as the only resuscitation step.

Results

Bolus lung inflation was sufficient for resuscitation, improving cardiac function and re-establishing adequate oxygen status to support life. Inflation steps could be repeated and survival times were approximately 3 times that of non-inflated lungs.

Conclusion

The properties and consequences of bolus lung inflation are described as a foundation for procedures or devices that can be useful in cases of severe laryngospasm and other cases of upper airway obstruction.

Level of Evidence

3.

Cannula cricothyroidotomy and rescue oxygenation with the Rapid-O2™ oxygen insufflation device in the management of a can't intubate/can't oxygenate scenario

We describe the successful use of cannula cricothyroidotomy and the Rapid-O2™ oxygen insufflation device (Meditech Systems Ltd, Dorset, UK) for rescue of a can't intubate/can't oxygenate (CICO) scenario in a patient with severe airway haemorrhage post-debridement of laryngeal amyloidosis. This case highlights the practical utility of a cannula technique for CICO rescue when appropriate equipment is used and when institutional measures are taken to prepare for this rare anaesthetic crisis.

Should Ongoing Airway Education be a Mandatory Component of Continuing Professional Development for College of Intensive Care Medicine Fellows?

This study aimed to determine whether airway education should be introduced to the continuing professional development (CPD) program for College of Intensive Care Medicine (CICM) Fellows. A random representative sample of 11 tertiary intensive care units (ICUs) was chosen from the list of 56 units accredited for 12 or 24 months of CICM training. All specialist intensive care Fellows (n=140) currently practising at the eleven ICUs were sent the questionnaire via email. Questionnaire data collection and post-collection data analysis was used to determine basic respondent demographics, frequency of certain airway procedures in the past 12 months, confidence with advanced airway practices in ICU, participation in airway education in the past three years, knowledge of can't intubate, can't oxygenate (CICO) algorithms, preference for certain airway equipment/techniques, and support for required airway education as a component of the CICM CPD program. All responses were tabled for comparison. Data was analysed to establish any significant effect of another specialty qualification and current co-practice in anaesthesia on volume of practice, confidence with multiple airway procedures, use of airway equipment, and support for airway education. In total, 112 responses (response rate 80%) to the questionnaire were received within four weeks; 107 were completed in full (compliance 96%). All results were tabled. There is currently widespread support amongst CICM Fellows for airway skills education as a CPD requirement for CICM Fellows. Volumes of practice and confidence levels with different airway procedures vary amongst Fellows and further support the need for education.